液相浸渗法制备CaAl12O19/（MgAl2O4-Al2O3）复相陶瓷

Preparation of CaAl12O19/（MgAl2O4-Al2O3） Ceramics by Liquid Infiltration

采用液相浸渗法制备了CaAl12O19/(MgAl2O4-Al2O3)复相陶瓷。研究了不同原料物质的量比(n(α-Al2O3)∶n(MgO)=1∶1、2∶1、3∶1、4∶1)对复相陶瓷的物相组成、显微结构和性能的影响。结果表明:试样中的MgAl2O4均不是理论配比,Al2O3含量不足时,生成了Ca12Al14O33和CaAl4O7。与未浸渗试样对比,生成的低熔点Ca12Al14O33可能促进了MgAl2O4晶粒的生长和发育;板片状CaAl12O19的生成虽然降低了试样的体积密度,但其强度反而增大,起到了增强、增韧的作用。随着复相材料中Al2O3含量的增加,试样的体积密度和抗折强度均逐渐增大。

CaAl12O19/(MgAl2O4-Al2O3)composite ceramics were prepared by liquid infiltration.The effects of different molar ratios(n(α-Al 2O 3)∶n(MgO)=1∶1,2∶1,3∶1,4∶1)of raw materials on the phase composition,microstructure and properties of composite ceramics were studied.The results showed that MgAl2O4 phases were confirmed as magnesia-rich or alumina-rich nonstoichiometric spinel.When the content of Al2O3 was insufficient,the Ca12Al 14O33 and CaAl4O7 phase were generated.Compared with the uninfiltrated samples,the low melting point Ca12-Al14O33 might promote the growth of MgAl2O4 grains.Although the formation of CaAl12O19 with plate-like morphology reduced the bulk density of samples,the strength increased instead,playing a role of strengthening and toughening.As the content of Al2O3 increased,the bulk density and flexural strength of the samples increased gradually.